Denmark’s Aalborg airport in the country’s north has been closed after unauthorised drones were seen in its airspace, according to local authorities.
Three other smaller airports in the country’s southern region – Esbjerg, Sønderborg and Skrydstrup – also reported drone activity, but were not closed.
The incident comes after the country’s Copenhagen airport was forced to close earlier this week due to a drone incursion, which the prime minister described as “the most severe attack on Danish infrastructure so far”.
Police said the devices could be seen from the ground, adding they couldn’t rule out the activity being a prank. They were investigating who was controlling them and their motive.
At least three flights have been diverted from Aalborg airport, with officials saying the Danish Armed Forces were affected as the airport is also used as a military base.
The North Jutland Police released a statement saying they were monitoring the situation at Aalborg closely but could not elaborate on how many drones were involved.
“We cannot yet comment on the purpose of the drones flying in the area, nor can we say anything about who the actor behind it is,” chief inspector Jesper Bøjgaard Madsen said.
“If we get the opportunity, we will take down the drones,” he added.
Police said they did not believe there was any danger to passengers at the airport or residents, but asked the public to keep their distance from the area.
Addressing the drone reports in Esbjerg, Sønderborg and Skrydstrup, police said they were “taking the situation seriously”, but could not comment on a motive.
They added that none of the airports had been closed and there was no danger to the public.
Of the three flights affected at Aalborg, two were sent back to Copenhagen, and another back to the town of Karup.
The agency that oversees European air traffic control said arrivals and departures at the airport would be stopped until 06:00 local time (04:00 GMT) on Thursday.
On Monday, Kastrup airport in Copenhagen was forced to shut for several hours following the sighting of a number of drones.
“It says something about the times we live in and what we as a society must be prepared to deal with,” Prime Minister Mette Frederiksen told reporters.
Russian involvement could not be ruled out, he added – although Kremlin spokesman Dmitry Peskov called the allegations “unfounded”.
Europe has been on high alert after several Nato member states reported Russian incursions in their airspaces.
Last week, Estonia and Poland requested a consultation with other Nato members, after Russia was accused of violating their airspace in separate incidents.
Romania, another Nato member, also said Russian drones had breached its airspace.
Russia denied violating Estonia’s airspace, while it insisted the Polish incursion was not deliberate. It did not comment on the Romania incident.
After meeting on Tuesday, Nato issued a statement condemning Russia’s actions and warned that it would use “all necessary military and non-military tools” to defend itself.
“Russia bears full responsibility for these actions, which are escalatory, risk miscalculation and endanger lives. They must stop,” it said.
Nato’s secretary general Mark Rutte said: “We are a defensive alliance, yes, but we are not naive, so we see what is happening.”
After his speech to the UN, Donald Trump suggested that Nato nations should shoot down Russian planes breaching their airspace.
